Thought suppression and suicidal ideation: preliminary evidence in support of a robust association

The suppression of unwanted thoughts appears to contribute to the development and maintenance of emotional disorders. This report tested the thought suppression paradigm in relation to suicidal ideation. Based on the ironic process theory, we hypothesized that the suppression of unwanted thoughts, especially suicidal thoughts, would associate with a higher frequency and a greater intensity of suicidal ideation.

Study 1 examined cross-sectional associations between self-reported thought suppression and the frequency of suicidal ideation in a nonclinical sample of 166 undergraduate students. Study 2 extended cross-sectional findings in an inpatient sample of 71 suicidal adolescents. Study 3 examined prospective associations between suicidal thought suppression and increases in self-reported suicidal ideation over a 4-week period in a separate nonclinical sample of 118 undergraduate students.

Findings across studies support a robust association between thought suppression and suicidal ideation, even controlling for general depressive symptoms. Participants in Studies 1 and 2 who endorsed greater tendencies toward suppression of thoughts, especially suicidal thoughts (Study 2), displayed higher concurrent levels of suicidal ideation. Participants in Study 3 who endorsed greater baseline tendencies toward suppression of suicidal thoughts displayed an increase in the severity of suicidal ideation over time.

Suppression of suicidal thoughts may represent 1 mechanism contributing to the persistence of suicidal ideation. Clinicians may wish to explore patients' reactions to suicidal ideation and consider acceptance-oriented strategies among patients who attempt to control unwanted suicidal thoughts.